Hidden photon measurements using the long-baseline cavity of laser interferometric gravitational-wave detector

Abstract

We suggest a new application for the long-baseline and high powered cavities in a laser-interferometric gravitational-wave~(GW) detector to search for WISPs (weakly interacting sub-eV particles), such as a hidden U(1) gauge boson, called the hidden-sector photon. It is based on the principle of a light shining through the wall experiment, adapted to the laser with a wavelength of 1064 or 532 nm. The transition edge sensor (TES) bolometer is assumed as a detector, which the dark rate and efficiency are assumed as $0.000001~\mathrm{s^{-1}}$ and 0.75, respectively. The TES bolometer is sufficiently sensitive to search for the low-mass hidden-sector photons. We assume that the reconversion cavity is mounted on the reconversion region of hidden-sector photons, which number of reflection and length are assumed as 1000 and 10, 100, and 1000m. We found that the second-point-five and the second generation GW experiments, such as KAGRA and Advanced LIGO with a regeneration cavity and TES bolometers. The expected lower bounds with these experiments wit the reconverted mirror are set on the coupling constant $\chi = 2 \times 10^{-9}$ for hidden-sector photon with a mass of $2 \times 10^{-5}$ eV within 95% confidence level. The third generation detector, Einstein Telescope, will reach $\chi = 1 \times 10^{-9}$ at a mass of $1 \times 10^{-5}$ eV within 95% confidence level. Although the operation and construction of the RC will demand dedicated optical configurations, the cavities used in GW detection are expected to measure the strong potential for finding the hidden-sector photons.